关键词: 工作模态参数, 拉普拉斯特征映射, 三维结构, 最小二乘广义逆, 低维嵌入

Abstract: To identify the operational modal parameters of linear time-invariant three- dimensional structures only from the stationary vibration response signals,a method based on Laplacian Eigenmaps was proposed.The vibration response data was regarded as the data set in the high-dimensional space,and the low-dimensional embedded data was found by using Laplacian Eigenmaps.Then,the natural frequency of the modal was identified from the modal response matrix corresponding to the low dimensional embedded matrix by using the single degree of freedom recognition technique.The modal shapes could be calculated from the Moore-Penrose matrix inverse of the low-dimensional embedding matrix.The simulation results of three-dimensional cylindrical shell showed that compared with equidistant mapping,Laplacian Eigenmaps was effectively identify the modal shape and natural frequency of the structure with lower time consumption and higher recognition accuracy.Compared with principal component analysis,Laplacian Eigenmaps had higher recognition accuracy.

Key words: operating modal parameters, Laplacian Eigenmaps, three-dimensional structure, the moore-penrose matrix inverse, low dimensional embedding